(a) Field of the Invention
The present invention relates to an electric remote control mirror apparatus for motor vehicles.
(b) Description of the Prior Art
Conventional electric remote control mirror apparatuses are widely used as an outside mirror, one of such the mirror apparatuses is disclosed in detail in the specification of U.S. Pat. No. 3,609,014.
Referring to FIGS. 1 to 4 a conventional electric remote control mirror apparatus is shown. FIG. 1 is a longitudinal cross sectional view, FIG. 2 a cross sectional view as seen in the direction of the arrow II--II in FIG. 1, FIG. 3 a cross sectional view as seen in the direction of the arrow III--III in FIG. 1, FIG. 4 a cross sectional view as seen in the direction of the arrow IV--IV in FIG. 1.
As seen from FIGS. 1 to 3, a mirror body 2 fixing a mirror 1 is pivotably supported through a pivot connection 4 with respect to a mirror housing 3. The line X--X' passing the center of the pivot connection 4 perpendicularly crosses the line Y--Y' passing the center. Boss portion 6 for a ball joint 5 is integrally formed on the mirror body 2 on each of the above two lines. The boss portion 6 is rearwardly extended to hold the ball joint 5 as shown in FIG. 1. The threaded rod 8 having a ball 7 for the ball joint 5 has a male screw on the peripheral surface thereof, and the threaded rod 8 can be screwed into a female screw provided on a gear 9, the gear 9 being rotatably mounted in a screw member 10. Upon actuation of motors 11 the screw members 10 are rotated to move the threaded rod 8 forwardly or backwardly thereby to incline the mirror body 2. Thus, by the movement of the threaded rod 8 connected to the ball joint 5 on the line X--X' of FIG. 3, the mirror body 2 is rotatably moved around the line Y--Y', and similarly the mirror body 2 is rotatably moved around the line X--X' by the movement of the threaded rod 8 connected to the ball joint 5 on the line X--X' of FIG. 3.
Therefore since the threaded rod 8 is moved forwardly or backwardly by the rotation of the screw member 10, it is inevitably necessary to stop the rotating motion of the threaded rod 8 per se. To this end the ball 7 of the ball joint 5 is held by a hair pin like spring 12 to avoid the rotating motion of the ball 7 i.e. the threaded rod 8. FIG. 4 is a cross sectional view as seen in the direction of the arrow IV--IV of FIG. 1, and the holding states of the spring 12 and the ball 7 are shown, wherein numeral 7a designates a slot formed on the ball 7.
According to the conventional electric remote control mirror apparatus mentioned above, the mirror body 2 to which the mirror 1 is fixed can be rotatably moved around the lines X--X' and Y--Y' respectively by respective and independent actuation of the two motors 11 and 11, thereby to remotely control the angle of the mirror 1. Therefore the apparatus is preferable as an outside mirror i.e. a rear view mirror for motor vehicles.
However, as is apparent from FIG. 1, since the pivot connection 4 is composed of a driving case 3a secured on the fixed mirror housing 3, having the projected ball, and a boss portion provided on the movable mirror body 2 for holding the projected ball provided on the driving-section case 3a, the dimension in the direction of pivot axis 13 becomes inevitably large, resulting in a heavy thickness of the mirror apparatus per se in the direction of the pivot axis 13. Further since the pivot connection 4 is constructed such that the rotating resistance of the pivot connection 4 is provided by the pressing force due to an adjusting screw 14, effected between the ball and the boss portion of the mirror body 2, the rotating resistance can be directly controlled by the adjusting screw 14. Therefore, it is actually difficult to delicately adjust the rotating resistance and further even after a correct adjustment thereof has been established a deviation of the adjustment due to looseness, wear and deformation of the screw 14 can undesirably occurred. In order to overcome the above-mentioned disadvantages, if a spring (not shown) is provided to obtain a stable rotating resistance by the spring force due to the spring, the dimension of the pivot connection in the direction of the pivot axis 13 is further undesirably increased.
As is apparent from the arrangement mentioned above, the rotation of the mirror body 2 around the pivot axis 13 is not restricted, resulting in unstable support for the mirror such that the mirror is not smoothly moved when operating the mirror and the inclination of the mirror undesirably changes when not operating the mirror. Furthermore, according to the arrangement of the hair pin-like spring 12 holding the slot 7a provided on the ball 7, the rotation of the threaded rod 8 per se is insufficiently stopped, especially when the threaded rod 8 is moved forwardly in the the right hand direction in FIG. 1 where the rotation of the threaded rod 8 is not sufficiently stopped. The results in unstable support of the mirror body 2 and allows change in the mirror's inclination.